We had a similar question in our group recently, only it had to be the mage making the attack. The issue we had with creatures was the variability of growth counters on some. Kralathor sitting back and eating 6 falcons, 6 bobcats, and 6 foxes wasn't really fair to the question being asked. Did not think of sacrificing Sardonyx, but I still got up pretty high through my own jank.
Forcemaster can make a 32 dice attack. Forcemaster carrying galvitar starts at 4 dice. +2 bear strength, +2 lion savagery, +2 ballad of courage, +1 marked for death, +1 gauntlets of strength, +1 hand of bim-shalla, +1 wolf's fury, +8 from four thoughtspores with power strike, +8 from four genie's using their wish on you, +2 from power striking yourself with a quick.
Throwing Sardonyx into the mix makes for a 40 dice 10 piercing attack from galvitar. Ouch.